OSI/MHS Gateway Programmatic Interface (GPI) Reference Manual

Glossary
OSI/MHS Gateway Programmatic Interface (GPI) Reference Manual—522223-001
Glossary-18
numeric O/R address
application has made no explicit assignment to that field after calling the SSNULL
procedure to initialize the structure.
numeric O/R address. An O/R address that identifies a user by a number. See also
mnemonic O/R address.
OBEY file. See command file.
object. In general, an entity subject to independent reference or control, and having well-
defined characteristics or behavior.
In DSM, an entity subject to independent reference and control by a subsystem: for
example, the disk volume $DATA or the data communications line $X2502. An object
typically has a name and a type known to the controlling subsystem.
In GPI, a collection of elements (called “attributes”) used for constructing messages.
See also root object, subobject, and superobject.
object identifier. In ASN.1, a set of values identifying an object in an ASN.1 abstract syntax
notation defined by the CCITT.
In the GPI, a unique identifier of a particular object generated by the GPI service when
the client program creates a new object, copies an object, or reserves an object. The
client program passes the object identifier to any GPI procedure operating on the object.
A GPI object identifier is not related to an ASN.1 object identifier.
object management. A means to operate on messages and their elements as objects.
object-name template. In DSM, a name that stands for more than one object. Such a name
includes one or more wild-card characters, such as * and ?. See also wild-card
character.
object tree. The internal form of an X.400 communication maintained by the GPI.
object type. In DSM, the category of objects to which a specific object belongs: for
example, a specific disk file might have the object type FILE, and a specific terminal
might have the object type SU (subdevice). A subsystem identifies a set of object types
for the objects it manages. The SCF interfaces to Compaq data communications
subsystems use standard keywords to identify the types. The corresponding
programmatic interfaces have object-type numbers (represented by symbolic names such
as ZCOM-OBJ-SU) suitable for passing to the SPI SSINIT procedure.
In the GPI, a category of objects having a common purpose and structure is called a
“class.”
octet. A sequence of eight bits. Also called a “byte” or “character.”
octet string. A string comprising octets.
open system. Any computer system that adheres to the OSI standards.